package com.lzx.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.lzx.reggie.common.BaseContext;
import com.lzx.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经登录的过滤器
 */
@Slf4j
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
public class LoginCheckFilter implements Filter {

    //进行路径匹配，支持通配符的写法
    private static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1.获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}", requestURI);

        //2.判断本次请求是否处理（检查登录装态）
        //2.1定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        //2.2判断
        boolean check = check(urls, requestURI);

        //3.如果不需要处理直接放行
        if (check) {
            log.info("本次请求：{}，不需要处理", requestURI);
            //放行
            filterChain.doFilter(request, response);
            return;
        }

        //4.判断登录状态，如果已经登录，则放行
        //4.1网页端
        Long empId = (Long) request.getSession().getAttribute("employee");
        //4.2移动端
        Long userId = (Long) request.getSession().getAttribute("user");

        //4.1网页端
        if (empId != null) {
            log.info("用户已经登录，用户id为：{}", empId);

            BaseContext.setCurrentId(empId); //设置值

            //放行
            filterChain.doFilter(request, response);
            return;
        }

        //4.2移动端
        if (userId != null) {
            log.info("用户已经登录，用户id为：{}", userId);

            BaseContext.setCurrentId(userId); //设置值

            //放行
            filterChain.doFilter(request, response);
            return;
        }



        //5.如果未登录，返回未登录结果。通过输出流的方式向客户端页面响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }

    /**
     * 路径匹配方法，检查本次请求是否放行
     *
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
